Climate Control System with Automatic Wiring Detection

ABSTRACT

A climate control system ( 10 ) includes an outdoor unit ( 14 ) and an indoor unit ( 12 ) having at least two fans ( 26,28 ). The fans ( 26,28 ) include control wiring ( 38,40 ) that is interchangeably connected to a control system ( 20 ), and feedback wiring ( 42,44 ) that is also interchangeably connected to the control system ( 20 ). The control system ( 20 ) is capable of automatically detecting the wiring configuration of the control wiring ( 38,40 ) and the feedback wiring ( 42,44 ). The climate control system ( 10 ) operates the fans ( 26,28 ) according to the detected wiring configuration to heat or cool an interior space.

BACKGROUND OF THE INVENTION

The present invention relates to a climate control system, and more particularly to a climate control system with automatic wiring detection.

Climate control systems such as heat pumps are used to heat interior spaces by transferring heat between the outside air and the inside air. As a result, climate control systems generally include an indoor unit and an outdoor unit. A refrigerant flows between the indoor unit and the outdoor unit. Within the indoor and outdoor units, the refrigerant passes through coils where it heats or cools the surrounding air.

Heating and cooling of the indoor space is accomplished by adjusting the pressure of the refrigerant within the coils to cause the refrigerant to undergo the phase changes of an evaporation cycle. To cool an indoor space, the climate control system utilizes a compressor to compress the refrigerant from a low-pressure gas to a high-pressure gas. This process causes the refrigerant to become hot. The hot refrigerant is passed through the coils of the outdoor unit. A fan in the outdoor unit forces outside air across the coils, causing the coils to cool and the refrigerant to condense into a liquid state. The liquid refrigerant is then passed through an expansion valve where it evaporates and cools even further to become a cold, low-pressure gas. The cold refrigerant is then passed through the coils of the indoor unit, where one or more fans force air from the interior space across the cool coils. The refrigerant absorbs some of the heat and thereby cools the air from the interior space. The cycle is repeated as needed.

To heat an interior space, the same process is used, except that the system is operated in reverse. In this case, the refrigerant is compressed and heated from a low-pressure gas to a high-pressure gas before entering the indoor unit. The heated refrigerant flows through the coils of the indoor unit, and indoor air is forced across the coils to heat the air and cool the refrigerant. The refrigerant is then passed through an expansion valve where it evaporates and cools to become a cold, low-pressure gas. The cold refrigerant then passes through coils in the outdoor unit where it is heated by the outside air. The cycle is repeated as needed.

One or more fans can be used in an indoor unit to force air across the coils of the indoor unit and to direct the heated or cooled air to desired locations within the interior space. Multiple fans are beneficial within an indoor unit because they allow the indoor unit to distribute heated or cooled air in more directions within the interior space. However, having more than one fan results in additional complexity and cost in the manufacturing and servicing of the indoor unit. Therefore, there is a need in the art for a climate control system that reduces the cost and complexity of manufacturing and servicing of an indoor unit having multiple fans.

BRIEF SUMMARY OF THE INVENTION

A climate control system includes automatic fan wiring detection that allows a plurality of fan motors to be interchangeably connected to a control unit of the climate control system. The fan motors each include control wiring terminated at a control wiring connector and feedback wiring terminated at a feedback wiring connector. The control unit includes control board connectors and feedback board connectors. The control wiring connectors are interchangeably connected to the control board connectors, and the feedback wiring connectors are interchangeably connected to the feedback board connectors. The control unit automatically detects the wiring configuration and operates the fans accordingly to heat or cool an interior space.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective diagram of a climate control system including an indoor unit and an outdoor unit.

FIG. 2 is a break-away perspective diagram of the indoor unit.

FIG. 3 is a wiring diagram illustrating connections between a control board of an indoor unit and fan motors.

FIG. 4 is a schematic diagram of the control board and associated components of the climate control system.

FIG. 5 is a flow chart illustrating the method of automatically detecting a wiring configuration of the fan motors.

DETAILED DESCRIPTION

FIG. 1 is a perspective diagram of climate control system 10. Climate control system 10 includes indoor unit 12, outdoor unit 14, and pipes 15. Climate control system 10 is a heat pump, chiller, air conditioner, or similar device that is capable of transferring heat between interior air and outdoor air to heat and/or cool an interior space. Indoor unit 12 includes a control unit, a coil, and fans, as described in more detail with reference to FIG. 2. Outdoor unit 14 includes a compressor, a coil, and a fan. A refrigerant is passed through the coils of the indoor unit and the outdoor unit, and is compressed by the compressor. Refrigerant flows within the coils of indoor unit 12 and outdoor unit 14, and through pipes 15 that connect between indoor unit 12 and outdoor unit 14.

FIG. 2 is a perspective diagram of indoor unit 12 broken apart to illustrate the internal components. Indoor unit 12 includes front panel 16, case 18, control box 20, coils 22, vertical flaps 24, fans 26 and 28, fan motors 30 and 32, frame 34, and mounting panel 36. Front panel 16 is a panel that directs the flow of air into indoor unit 12. Front panel 16 is pivotally connected to the lower front side of case 18, such that the upper end of front panel 16 pivots out and away from the upper end of case 18. Control box 20 contains the control circuitry for climate control system 10. Control box 20 is connected inside a lower portion of case 18, with coils 22 mounted above control box 20 to case 18 and frame 34. Coils 22 contain a refrigerant which heats or cools the coils, thereby heating or cooling air from the interior space as it passes by. Vertical flaps 24 mount on the sides of indoor unit 12 and direct the flow of air out from indoor unit 12. Adjacent to vertical flaps 24 and within indoor unit 12 are fans 26 and 28. Fans 26 and 28 pull air in through the front and out through the sides of indoor unit 12. Fan 26 is connected to fan motor 30 and fan 28 is connected to fan motor 32. Fans 26 and 28 and fan motors 30 and 32 are supported by frame 34 which is connected to case 18. Fan motors 30 and 32 each include two sets of wires including control wiring 38 and 40 and feedback wiring 42 and 44. Each of wiring 38, 40, 42 and 44 is terminated in a connector that is connected to control box 20. Mounting panel 36 forms a back panel of indoor unit 12 that can be mounted to a wall or other indoor structure.

FIG. 3 is a wiring diagram illustrating connections between control board 50 and fan motors 30 and 32. Control board 50 is a printed circuit board within control box 20 (shown in FIG. 2). Control board 50 includes microcontroller 52, fan drivers 54 and 56, control board connectors 58 and 60, and feedback board connectors 62 and 64. Fan motors 30 and 32 include rotation sensors 66 and 68, such as Hall-effect sensors, that detect the rotational velocity (e.g. rotations per minute or “RPM”) of fan motors 30 and 32. Fan motor 30 includes control wiring 38 terminated at control wiring connector 70 and feedback wiring 42 terminated at feedback wiring connector 72. Fan motor 32 includes control wiring 40 terminated at control wiring connector 74 and feedback wiring 44 terminated at feedback wiring connector 76.

Microcontroller 52 controls the operation of fan motors 30 and 32 (and associated fans 26 and 28, shown in FIG. 2) through fan drivers 54 and 56. Fan motors 30 and 32 require more power to operate than directly available from microcontroller 52, and therefore fan drivers 54 and 56 are provided to deliver the necessary power. Fan drivers 54 and 56 include, for example, an optical coupler for isolating microcontroller 52 and other low-voltage electronics from the higher-voltage alternating current (“AC”) power used by fan motors 30 and 32, and a triac, transistor, or solid state relay for delivering the necessary AC power. Fan drivers 54 and 56 are each connected to board control connectors 58 and 60 respectively.

Microcontroller 52 receives feedback from rotation sensors 66 and 68 that informs microcontroller 52 of the rotational velocity of fan motors 30 and 32 respectively. Feedback is provided by rotation sensors 66 and 68 of fan motors 30 and 32 through feedback wiring 42 and 44, feedback wiring connectors 72 and 76, and feedback board connectors 62 and 64, to microcontroller 52. Rotation sensors 66 and 68 generate pulses representative of the rotational velocity, such as six pulses per rotation. Microcontroller 52 receives and counts the number of pulses over a period of time to determine the current rotational velocities of fan motors 30 and 32.

During manufacturing of climate control system 10, fan motors 30 and 32 are connected to control board 50. Specifically, control wiring connectors 70 and 74 are connected to control board connectors 58 and 60, and feedback wiring connectors 72 and 76 are connected to feedback board connectors 62 and 64.

To save time, and reduce the possibility of errors, control wiring connectors 70 and 74 can interchangeably be connected with control board connectors 58 and 60. Similarly, feedback wiring connectors 72 and 76 can interchangeably be connected with feedback board connectors 62 and 64.

For example, during the installation of fan motor 30, both control wiring connector 70 and feedback connector 72 are connected to control board 50. To do so, control wiring connector 70 can be inserted into either control board connector 58 or control board connector 60. Similarly, feedback connector 72 can be inserted into either feedback board connector 62 or feedback board connector 64. The same is true for the installation of fan motor 32, so long as only one wiring connector is inserted into one board connector.

In one embodiment, control wiring connectors 70 and 74 are shaped and/or sized differently from feedback wiring connectors 72 and 76 such that they will only fit into the corresponding control board connectors 58 and 60 and feedback board connectors 62 and 64 respectively. In this embodiment it would be impossible for an installer to accidently insert feedback wiring into a control board connector, or insert control wiring into a feedback board connector.

After all connectors have been installed and climate control system 10 has been turned on, microcontroller 52 automatically detects the wiring configuration of fan motors 30 and 32 with respect to control board 50. A method of automatically detecting the wiring configuration is described in more detail with reference to FIG. 5.

One of the benefits realized with interchangeable connectors is that fan motors 30 and 32 can be identical. This reduces inventory costs because only a single part number needs to be maintained in stock, and reduces complexity in manufacturing because no distinction has to be made between fan motors. An alternative method would be to have non-interchangeable connectors that are shaped or sized such that they would only fit into the appropriate location on circuit board 50. However, this alternative increases costs and complexity because fan motor 30 would have a different control wiring connector and feedback wiring connector than fan motor 32, requiring that two part numbers be kept in stock and distinguished from each other. In addition, different board connectors (both control connectors and feedback connectors) would also have to be maintained in stock and distinguished from each other. These problems are solved by providing interchangeable connectors.

The same benefits apply not only during manufacturing, but also during the repair of climate control system 10. If a fan motor burns out, or other repairs are necessary, repair personnel need not distinguish between multiple types of fan motors, because fan motors are interchangeable. In addition, repair personnel need not waste time figuring out which board connection is appropriate, because any available board connection can be used, so long as the wiring connector fits into the board connector.

FIG. 4 is a schematic diagram of control board 50 and associated components of climate control system 10. Control board 50 includes microcontroller 52 and fan drivers 54 and 56. Climate control system 10 also includes, power input 80, line filter 82, power supply 84, power supply 86, driver chip 88, switches and relays 90, communication circuit 92, stepper motors 93, temperature sensors 94, current transformer 96, and interface circuitry 98.

AC power is supplied to climate control system 10 through power input 80 where it is fused and then filtered by line filter 82. The power is converted to the appropriate levels by power supplies 84 and 86. Power supply 84 supplies higher voltage devices with 14 volt and 16 volt power, and power supply 86 supplies lower voltage power to microcontroller 52 and other digital components.

Microcontroller 52 is a digital processing circuit capable of operating software or firmware algorithms to control the operation of climate control system 10. Microcontroller 52 includes random-access memory (RAM) 100 and read-only memory (ROM) 102 and is connected to electrically erasable programmable read-only memory (EEPROM) 104. Control algorithms are stored within ROM 102 that are executed by microcontroller 52 to properly operate climate control system 10. Wiring configuration data is stored within RAM 100 after the wiring configuration algorithm has been successfully completed. The wiring configuration algorithm is described in more detail with reference to FIG. 5. Additional configuration data relating to the specific functions and capabilities of climate control system 10 are stored within EEPROM 104, readable by microcontroller 52.

Microcontroller 52 also includes various input and output ports through which microcontroller 52 can interact with other components within climate control system 10. Microcontroller 52 utilizes driver chip 88 to operate and control switches and relays 90, communication circuit 92, and stepper motors 93. Driver chip 88 is capable of handling the high current demands of relays, communication circuits, and motors as instructed by microcontroller 52. Switches and relays 90 are used to control a variety of components including the compressor, a reversing valve (to switch between heating and cooling of the indoor space), the outdoor fan, indoor air quality features such as air filters, and a condensate pump. Communication circuitry 92 can also be used to communicate with components of outdoor unit 14. Stepper motors 93 are controlled by microcontroller 52 through driver chip 88. Stepper motors 93 operate, for example, to adjust the position of the front panel, vertical flaps, and louvers (not shown) used to further control the direction of airflow into or out from climate control system 10.

As described above, microcontroller 52 controls the operation of fan motors 30 and 32 through fan drivers 54 and 56, and receives feedback from rotation sensors 66 and 68 associated with fan motors 30 and 32. Rotation sensors 66 and 68 are, for example, Hall-effect sensors.

Microcontroller 52 receives inputs from temperature sensors 94 and current transformer 96. Temperature sensors 94 provide temperature readings from various locations of climate control system 10, such as air temperature as it enters indoor unit 12, refrigerant/coil temperatures, and any other desired temperature measurements. Current transformer 96 provides an indication to microcontroller 52 of when a defrost cycle of outdoor unit 14 can be terminated. The defrost cycle is used to remove ice buildup from the coils of outdoor unit 14.

Microcontroller 52 interacts with various components generally defined as interface circuitry 98. Interface circuitry 98 provides various methods of communication between a person (such as a user, manufacturer, or repair person), and climate control system 10. Interface circuitry 98 includes buzzer 106, status light-emitting diode (LED) 108, programming interfaces 110, building management system input 112, and display board 114. Buzzer 106 is used by microcontroller 52 to generate an audible sound to alert a person that something has changed (such as when a user requests an operating mode change) or that attention is required.

Microcontroller 52 utilizes status LED 108 to provide a visual signal to communicate with a person. For example, status LED 108 flashes periodically to indicate that it is functioning properly. Status LED 108 will also flash to provide diagnostic codes in the case of a malfunction.

Programming interfaces 110 provide input and output ports for programming microcontroller 52 and EEPROM 104 with desired configuration settings, programming algorithms, or for communicating any other desired data such as with diagnostic equipment.

Building management system input 112 provides an input to microcontroller 52 to request operating mode adjustments. For example, if climate control system 10 is operating in a hotel, the front desk can utilize a building management system to turn off climate control system 10 when the room is not being used or in the case of a fire.

Display board 114 is connected to microcontroller 52 and includes infrared receiver 116, manual override switch 118, light-emitting diodes (LEDs) 120, and display configuration jumper 122. Infrared receiver 116 receives inputs from infrared remote control 124. The inputs instruct microcontroller 52 of the desired operating modes or configuration settings. Manual override switch 118 allows a user to manually change operating modes, such as to turn the climate control system on or off without a remote control. LEDs 120 provide a visual indication of the status of control unit 20, such as to indicate if climate control system 10 is turned on and to display diagnostic codes in the case of a malfunction. Display configuration jumper 122 provides an input to microcontroller 60 telling it which of various display board models are currently connected.

FIG. 5 is a flow diagram illustrating method 140 for automatically detecting the wiring configuration of fan motors 30 and 32 and adjusting the wiring configuration settings of climate control system 10 accordingly. The method is stored as executable code in ROM 102 and executed by microcontroller 52.

Method 140 begins when climate control system 10 is turned on (step 142). System 10 first determines whether the feedback inputs (the inputs to microcontroller 52 associated with connectors 62 and 64) have already been assigned to the fans (step 144). If they have, climate control system 10 continues with normal operation (step 146). If they have not, then climate control system 10 continues the automatic detection of the wiring configuration. In this step (step 144), microcontroller operates to bypass the wiring detection only if climate control system 10 has not been disconnected from power source 80 since the last time that wiring detection was successfully completed. The wiring configuration is rechecked any time that climate control system 10 is disconnected from power source 80 because of the possibility that a person has reconfigured the wiring while the power was out. If, however, climate control system 10 remains plugged into power source 80, but is merely turned off and then back on, the wiring does not have to be rechecked because it is assumed that no repair or service has been performed.

If microcontroller 52 determines that feedback inputs have not already been assigned to fans (step 144), microcontroller 52 turns on a first fan connected to connector 58 (step 148). For purposes of the following discussion, the fan connected to connector 58 is referred to as the first fan (fan 1), and the fan connected to connector 60 is referred to as the second fan (fan 2). Also, the feedback provided by rotation sensors 66 and 68 through connectors 62 and 64 are referred to as the first and second feedback inputs (input 1 and input 2).

When the first fan is turned on, it is set to a relatively high speed, such as 1050 rotations per minute (RPMs) (step 148). During this time, the second fan remains off. Microcontroller 52 then checks for feedback (if any) at the first input and the second input (step 150). Although only one fan i turned on, it is possible that both inputs will have feedback indicating that both fans are rotating. The reason for this is that the air flow generated from one fan can cause the other fan to rotate. However, the rotation of the second fan will be much less than the first fan. Microcontroller 52 compares the first input with the second input, and determines which one is greater (step 150). In one embodiment, microcontroller 52 checks to see which input is at least 500 RPMs greater than the other.

If the first input is greater than the second input, then microcontroller 52 assigns the first input to the first fan, and stores the result in RAM 100 (step 152). If the second input is greater than the first input, then microcontroller 60 assigns the second input to the first fan (step 154). If neither input is greater it indicates that an error has occurred, such as the first fan not being connected, a rotation sensor not being connected, or a malfunction in these or components of climate control system 10 has occurred. As a result, microcontroller 52 turns off fan 1 (step 155), turns on fan diagnostics (step 156), and aborts further wiring configuration detection.

When in fan diagnostics mode 156, climate control system 10 will not operate to heat or cool the indoor space. Instead, the user is informed that an error has occurred through one or more methods such as through buzzer 106, status LEDs 108, and/or LEDs 120 of display board 114. In one embodiment, LEDs 108 and 120 flash a diagnostic code that indicates to the user that the there is a problem with the fan motor wiring. Climate control system 10 remains in the fan diagnostic mode (step 156) until climate control system 10 is turned off and turned back on, in which case microcontroller repeats method 140 beginning at step 142.

If the assignment of an input to the first fan was successful (steps 152 or 154), the first fan is turned off (step 158) and the second fan is turned on (step 160). Microcontroller 52 receives an indication of the respective fan speeds from the first and second inputs, and determines which input is greater (step 162). In one embodiment microcontroller 52 determines which input is at least 500 RPM greater than the other. If the first input is greater than the second input, microcontroller 52 assigns the first input to the second fan (step 166) and stores the result in RAM 100. If the second input is greater than the first input, microcontroller 52 assigns the second input to the second fan (step 168) and stores the result in RAM 100. If neither of the inputs are greater, an error has occurred and microcontroller 52 turns off fan 2 (step 167), and turns on fan diagnostics (step 156).

If an input was successfully assigned to the second fan, then the second fan is turned off (step 168). Microcontroller 52 next performs the final checks to ensure that the fan wiring detection was successful. Microcontroller 52 first verifies that both inputs were assigned to a fan (step 170). In other words, the first input should be assigned to the first fan or the second fan, and the second input should be assigned to the first fan or the second fan. If not, then an error has occurred and microcontroller 52 turns on fan diagnostics (step 156).

If both inputs are assigned to a fan, then microcontroller 52 next verifies that the inputs are not both assigned to the same fan (step 172). In other words, the first and second inputs should not both be assigned to the first fan, nor should they both be assigned to the second fan. If they are, an error has occurred and microcontroller 52 turns on fan diagnostics 156. If each input is appropriately assigned to a unique fan then the fan wiring detection has been successful, and climate control system 10 continues normal operation (step 146).

Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. 

1. A climate control system comprising: an indoor unit for adjusting the temperature of indoor air, the indoor unit having a first fan and a second fan, each fan having control wiring; an outdoor unit for transferring heat with outdoor air; and a control system for controlling the operation of the indoor unit and the outdoor unit, the control system comprising: a first board connector and a second board connector, each board connector interchangeably connected to the control wiring of the first fan motor and the control wiring of the second fan motor; and a fan controller connected to each board connector, the fan controller for controlling the operation of the first fan and the second fan and for automatically detecting a wiring configuration of the control wiring of the first and second fan motors.
 2. The climate control system of claim 1, wherein the fan controller comprises: a microcontroller; a first fan driver connected to the fan wiring of the first fan and the microcontroller; and a second fan driver connected to the fan wiring of the second fan and the microcontroller.
 3. The climate control system of claim 1, the control wiring further comprising feedback wiring.
 4. The climate control system of claim 3, each of the fans further comprising a rotation sensor connected to the respective feedback wiring.
 5. The climate control system of claim 1, the fans further comprising feedback wiring.
 6. The climate control system of claim 5, the control system further comprising a first feedback board connector and a second feedback board connector, each feedback board connector connected to the fan controller and interchangeably connected to the feedback wiring of the first fan and the feedback wiring of the second fan, wherein the fan controller is configured to automatically detect a wiring configuration of the feedback wiring of the first and second fans.
 7. A fan control system comprising: a first fan and a second fan; a first fan motor and a second fan motor, each fan motor having control wiring terminated in a wiring connector; a fan motor controller for automatically detecting a wiring configuration of the first and second fan motors; and a first board connector and a second board connector connected to the fan motor controller, wherein the wiring connectors are interchangeably connected to the first board connector and the second board connector.
 8. The fan control system of claim 7, wherein the fan motor controller comprises: a microcontroller; a first fan driver connected to the microcontroller; and a second fan driver connected to the microcontroller.
 9. The fan control system of claim 7, the fan motors further comprising a motor rotation sensor.
 10. The fan control system of claim 9, the rotation sensor comprising a Hall-effect sensor.
 11. The fan control system of claim 8, wherein each fan driver comprises: an optical coupler for isolating the fan motor from the microcontroller; and means connected to the optical coupler for delivering power to the fan motor.
 12. The fan control system of claim 11, wherein the means for delivering power is selected from the group consisting of a triac, a transistor, and a relay.
 13. The fan control system of claim 7, the control wiring comprising feedback wiring.
 14. The fan control system of claim 7, each fan motor further comprising first feedback wiring terminated in a feedback wiring connector.
 15. The fan control system of claim 7, further comprising a first feedback board connector and a second feedback board connector, each feedback board connector connected to the fan motor controller, the feedback wiring of each fan motor being interchangeably connected to the first feedback board connector and the second feedback board connector.
 16. A method of automatically detecting a wiring configuration of multiple fan motors, each fan motor having a rotation sensor, the method comprising: i. turning on a first fan motor; ii. detecting the rotation of the fan motor with one of the rotation sensors; iii. associating the rotation sensor of step ii with the first fan motor; iv. turning off the first motor; and v. repeating steps i-iv for each fan motor.
 17. The method of claim 16, further comprising: vi. verifying that each rotation sensor is associated with a unique fan motor.
 18. The method of claim 17, step vi comprising: verifying that each rotation sensor is assigned to a fan motor; and verifying that no two rotation sensors are assigned to the same fan motor.
 19. The method of claim 18, further comprising initiating a fan diagnostics mode if any steps fails.
 20. The method of claim 16, further comprising operating the fans according to the detected wiring configuration if all steps are successful. 